The manatee's body is streamlined--full around the middle and narrowing to a paddle-shaped tail

Manatees are grayish-brown. Amazonian manatees usually have white or pink patches on the belly and chest. Organisms such as algae, which may grow on the skin of these slow-moving individuals, help determine their coloration.
The two small pectoral flippers on a manatee's upper body are used for steering. These flexible flippers may also be used for bringing food to the manatee's mouth and for guiding movement along a waterway's bottom.
West Indian and West African manatees have three or four fingernails, similar to the toenails on an elephant's feet, at the tips of their flippers. Amazonian manatees do not have fingernails.
Manatee flippers have five digits that are covered by a thick layer of skin. This bone structure is similar to that of toothed whales, seals, and sea lions. Hind limbs are absent. Vestigial pelvic bones, which aren't connected to the vertebral column, are found deep in the pelvic musculature.
Manatees have no externally discernible neck. Manatees don't have external ear flaps. The opening to the ear canal is very small. Two nostrils lie on top of the head at the end of the snout.
Manatees have a large flexible upper lip. Their lips help guide vegetation into their mouth. Vibrissae (whiskers) are found on the surface of this lip. Each vibrissa is seperately attached to the nerve endings and has its own blood supply in the follicle.
Small eyes (about 0.8 in. or 2 cm in diameter) are located on the sides of the head.
A manatee's only teeth are 24 to 32 molars located in the back of the mouth. The front molars in each row are continually being worn down by the abrasive plants that the manatee eats. As the teeth wear down new molars grow in the back of the mouth and move forward. The replacement process continually provides new chewing surfaces as the teeth wear down, and continues throughout the manatee's life. In addition to molars, manatees have horny, ridged pads at the front of the upper and lower jaws.
A manatee swims by moving its large paddlelike tail in an up-and-down motion. A manatee has sparse hair scattered over its torso.

All sirenians are herbivores. They feed on a wide variety of submerged, emergent, floating, and shoreline vegetation.
Manatees in Florida feed on over 60 species of plants. These include turtle grass, manatee grass, shoal grass, mangrove leaves, various algae, water hyacinth, and water hydrilla. All manatees eat vegetation.
Manatees avoid specific plants, such as spatterdock and waterpennywort, that contain natural toxins. Antillean manatees have been known to eat fish from nets.

Manatees consume about 4% to 9% (32 to 108 lb. or 15-49 kg for an adult manatee) of their body weight in wet vegetation daily. Amazonian manatees living in deep bodies of water apparently fast during the dry season (November and December). During the dry season the water level drops as much as 30 to 50 ft. (9-15 m), and manatees in these areas don't have access to living vegetation.

Manatees feed off the bottom, in the water column, and at the surface. They have even been known to crop overhanging branches, consume acorns, and haul themselves partially out of the water to eat bank vegetation. Manatees use their front flippers and large, flexible lips to manipulate vegetation.
Horny, ridged pads at the front of a manatee's palate (roof of the mouth) and lower jaw break vegetation into small pieces. Behind these pads, molars grind the food.

Both the West Indian and West African manatees may require a source of fresh water for drinking. Manatees have been seen drinking fresh water from hoses, sewage outfalls, culverts, and other fresh water sources and also congregating at river mouths. Most scientists agree that manatees must periodically have access to fresh water.

The most important bond in a manatee's life is with its mother. About 13 months after mating a female manatee gives birth to a baby, called a calf, that can weigh 60 to 70 pounds (about 30+ kg) and measure 3 to 4 feet (about 1 meter) in length.
Baby manatees are born with a much darker shade of gray skin than their mothers. It lightens after a month or so. Baby manatees are able to swim, see and hear right away. They also are born with a full set of teeth. At first, they need to breathe more often than adults, but soon they learn to hold their breath longer.
Like all other mammals, they feed on their mother's milk for the first part of their lives, suckling at nipples beneath her flippers. Manatee milk is much richer than the cow milk people are used to at their breakfast table. When the calf is a few weeks old, it begins to eat sea grasses like an adult, but it will be months before it is weaned.
A newborn manatee will stay with its mother for about two years before setting off on its own. Then the mother may have another baby, but the older calf may sometimes return to visit. Most manatees have only one baby at a time; twins are rare. However, if a mother manatees is killed or injured, another will sometimes take care of the orphaned baby.
If a calf gets tired, it can ride on its mother's back for awhile, or, if they are both resting, curl up on her broad, flat tail. Manatees can keep having babies for many years. The most known born to a single manatee is six. This record is held by Juliet, a manatee living at the Miami Seaquarium. The first manatee born in captivity belonged to her, and her 6th calf was born on March 13, 1989.

http://www.savethemanatee.org/

http://worldwildlife.org